A5086638422- Mechanical Behavior of Composites
- Ultrasonics and Acoustic Wave Propagation
- Structural Response to Dynamic Loads
- High-Velocity Impact and Material Behavior
- Non-Destructive Testing Techniques
- Icing and De-icing Technologies
- Structural Health Monitoring Techniques
- Geophysical Methods and Applications
- Structural Analysis of Composite Materials
- Fatigue and fracture mechanics
- Smart Materials for Construction
- Transportation Safety and Impact Analysis
- Composite Structure Analysis and Optimization
- Structural Load-Bearing Analysis
- Carbon Nanotubes in Composites
- Structural Behavior of Reinforced Concrete
- Cellular and Composite Structures
- Material Properties and Applications
- Mechanical stress and fatigue analysis
- Force Microscopy Techniques and Applications
- Composite Material Mechanics
- Tribology and Wear Analysis
- Advanced Sensor and Energy Harvesting Materials
- Fiber-reinforced polymer composites
- Electrical and Bioimpedance Tomography
University of California, San Diego
2014-2024
Jacobs (United States)
2022
University of California, Berkeley
2018-2019
National Institute for Materials Science
2017
Purdue University West Lafayette
2002-2011
Vaughn College of Aeronautics and Technology
2006
University of California, Santa Barbara
1999-2001
The strain-dependent electrical resistance characteristics of multi-walled carbon nanotube (MWCNT)/polymer composite films were investigated. In this research, polyethylene oxide (PEO) is used as the polymer matrix. Two representative volume fractions MWCNT/PEO selected: 0.56 vol% (near percolation threshold) and 1.44 (away from MWCNT. An experimental setup which can measure strain simultaneously continuously has been developed. Unique repeatable relationships in versus obtained for multiple...
Hail ice impacts are a realistic threat to exposed composite structures such as aircraft fuselage and wing skins, leading-edgeandcontrolsurfaces,enginenacelles,andfanblades.Toshedsomelightontothislittle-understood (and unavoidable ) threat, experimental, numerical, analytical investigations have been conducted. Experiments in whichcarbon/epoxy compositepanelswereimpacted by icespheresathigh velocity (30‐200m/s)wereconducted measure 1)the impact energy at which damage initiates, 2 the...
Reduction of contact resistance is demonstrated at Cu–Cu interfaces using a multiwalled carbon nanotube (MWCNT) layer as an electrically conductive interfacial material. The MWCNTs are grown on copper substrate plasma enhanced chemical vapour deposition (PECVD) with nickel the catalyst material, and methane hydrogen feed gases. showed random growth directions had bamboo-like structure. Contact reaction force were measured for bare interface Cu–MWCNT–Cu function probe position. For apparent...
In this article, an approach based on array of macro-fiber composite (MFC) transducers arranged as rosettes is proposed for high-velocity impact location isotropic and aircraft panels. Each rosette, using the directivity behavior three MFC sensors, provides direction incoming wave generated by source a principal strain angle. A minimum two sufficient to determine intersecting directions. The piezoelectric rosette easier implement than well-known time-of-flight-based triangulation acoustic...
This paper discusses a non-destructive evaluation (NDE) technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI) from ground service equipment (GSE), such as heavy cargo loaders and other equipment. The test typically include skin, co-cured stringers, C-frames that are bolt-connected onto skin with shear ties. inspection exploits waveguide geometry these by utilizing ultrasonic guided waves line scan approach. Both contact...
Abstract The objective of this study is to develop and validate a noncontact, nondestructive inspection imaging method for rapidly assessing the subsurface condition carbon fiber-reinforced polymer (CFRP) composite structures. works on principle planar electrical capacitance tomography (ECT). Unlike conventional ECT systems, electrodes are arranged rectangular surface in form grid. volume one side electrode plane interrogated with an electric field, mutual capacitances between measured....
Abstract The effect of bondline thickness on the critical strain energy release rate (CSERR) was investigated using aluminum adherends and an epoxy adhesive. Complete mixed Mode I/II fracture envelopes for adhesive thicknesses ranging from 0.203 to 1.52 mm were developed double cantilever beam (DCB), mixed-mode bending (MMB), end notch flexure (ENF) tests methods. Bondline strongly affects CSERR different amounts II component. Pure had largest showed monotonic increase with thickness,...
The dynamic compressive behavior of ice is investigated using a large-sized (37 mm in diameter) modified aluminum split Hopkinson pressure bar (SHPB) with pulse shaper at the strain rate from 500 s-1 to 1200 s-1. A series relatively stable experimental results strength versus and linear fitting curve have been obtained by controlling data scatter within 25%. composition incident wave has discussed. effects diameter velocity striker tested. properties principles different stage elaborated...
The technique of piezoelectric rosettes has been developed for the location acoustic emission sources. Since rosette-based source algorithm is not dependent on wave velocity, method lends itself to monitoring complex composite structures where velocity can change with propagation direction (due anisotropy) or along path tapered and multilayered geometries). This article presents results from “blunt” impact tests conducted a curved carbon fiber–reinforced plastic panel co-cured stiffeners...